The software includes 40 exercises, broken into four categories: balance, aerobics, strength training and yoga. Tying them together is a comprehensive monitoring program that stores your results and graphs them over time. Unless you're in extraordinary condition, your first few minutes with Wii Fit will not leave you smiling. The software centers on body mass index (BMI), a ratio of weight to height that's supposed to indicate how much body fat you're carrying. If you've ever figured your BMI (with an online calculator like this one), you know it's an unforgiving, unrealistic bastard of a measurement. After the program tells you you're overweight or obese (trust me, it will), figure out how much you'd have to lose to hit "normal weight." In my case, even if I were to get down to a weight I know looks reasonable on me, I'd have to grow six inches, and exercises for spinal lengthening are strangely missing from the program. Still, the stat does offer a way to monitor your progress.